In order to determine the orientation of the rotational axis and the shape of the asteroid, we used the amplitude-magnitude (

From the lightcurves, we obtain the magnitude

If we assume the smaller axis

In some cases the extrema of the theoretical curves seem to be overestimated with respect to the observed values. This fact depends on the computing program that, in the absence of observed values at the longitudes of the maximum or the minimum, takes into account the slope of the ascending or descending branches.

From the axes ratios it is possible to obtain the value of the aspect angle (with an uncertain definition of the north or south pole) and hence the pole longitude.

Following Zappalà et al. (1990) suggestions, we have corrected the lightcurve amplitude for its dependence on the phase angle, by means of the relationship where is the observed lightcurve amplitude, is the solar phase angle and

In Table 1, for each asteroid, the references of the lightcurves used for the
estimation of the *V* magnitude and for the construction of the
plots are reported. The symbol before the author's name is that used in
the corresponding plots. Only lightcurves at least 90%
covered were utilized. Due to the available lightcurves, their minimum number
(at least three) necessary for applying the (*AM*) method and to their
distribution in longitude, it was possible to compute the pole coordinates
and the axes ratios only for 30 asteroids. In
Fig. 1, using different
symbols for different authors as indicated in Table 1, the
plots of these asteroids are reported. The adopted values are the
mean values computed over the duration of each lightcurve.
The filled symbols indicate the observed values of the amplitude *A*, the
empty ones the corresponding values at longitudes , the
continuous and dashed
(in the case of two solutions) lines the theoretical curves.

Figure 1:
Amplitude-longitude plots of the asteroid to
which it was possible to apply the (AM) method. The filled symbols, as
reported in Table 1, indicate the observed values of the amplitude A,
the empty ones the corresponding ones at longitudes , the continuous and (in the case of two solutions) dashed lines the
theoretical curves |

Copyright The European Southern Observatory (ESO)